/Engine/Source/Runtime/Engine/Classes/Engine/AssetManager.h
Get the encryption key guid attached to this primary asset. Can be invalid if the asset is not encrypted
virtual void GetCachedPrimaryAssetEncryptionKeyGuid ( [FPrimaryAssetId](API\Runtime\CoreUObject\UObject\FPrimaryAssetId) InPrimaryAssetId, [FGuid](API\Runtime\Core\Misc\FGuid) & OutGuid )